UNITED NATIONS - A UN Security Council committee on Wednesday added three "very significant" North Korean state companies to a UN blacklist of firms banned from international trade, US Ambassador to the United Nations Susan Rice told reporters.

The decision by the Security Council's North Korea sanctions committee came after China consented to sanctions on the trio of companies. It falls far short of the roughly 40 firms the United States, European Union, South Korea and Japan had wanted to blacklist after Pyongyang's recent rocket launch.

China, North Korea's protector on the Security Council and a permanent veto-wielding member, had initially consented to sanction only two new companies but eventually agreed to blacklist one additional firm, council diplomats told Reuters on condition of anonymity.